| 摘要 |
PROBLEM TO BE SOLVED: To provide a wire rod of a low-carbon sulfur-based free cutting steel, having excellent machinability even when toxic Pb is not added thereto, and to provide a suitable manufacturing method therefor. SOLUTION: The wire rod of the low-carbon sulfur-based free cutting steel comprises, by mass%, 0.02-0.15% C, 0.50-2.0% Mn, 0.05-0.20% P, 0.15-0.50% S, 0.01% or less Si, 0.01% or less Al, 0.002-0.02% N, 0.01-0.03% O, and the balance Fe with unavoidable impurities; and is drawn after hot rolling or hot forging, to have, when d (mm) is defined as a diameter of the steel wire, 2.8*logd or more of an average width (μm) of sulfide-based inclusions in a region from 0.1 mm to d/8 deep from an outer surface, and have the yield ratio of the wire rod of 0.96 or higher. COPYRIGHT: (C)2003,JPO
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